<!DOCTYPE html>
<html lang="zh">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<link rel="stylesheet" href="./bootstrap-3.4.1-dist/css/bootstrap.css">
</head>
<body>
    
<!-- 
    按钮
     <a>、<button> 或 <input>  元素都可以作为按钮
     基础类: btn 
     按钮颜色：btn-default btn-primary btn-success btn-info btn-warning btn-danger
     按钮尺寸：
 -->

<div class="container">
  <button class="btn btn-default">按钮1</button>
  <button class="btn btn-primary">按钮2</button>
  <button class="btn btn-success">按钮3</button>
  <button class="btn btn-info">按钮4</button>
  <button class="btn btn-warning">按钮5</button>
  <button class="btn btn-danger">按钮6</button>

  <button class="btn btn-lg">超大按钮</button>
  <button class="btn">默认按钮</button>
  <button class="btn btn-sm">小按钮</button>
  <button class="btn btn-xs">超小按钮</button>
   
</div>

</body>
</html>